How To Clean Beer Bottles Before Bottling

It is said that two-thirds of the work done at any brewery should be cleaning. Thankfully, when it comes to homebrewing, things are rather less onerous. However, the principle remains – if you don't clean it properly, you're probably just setting yourself up for spoiled goods down the line. Read up on our expert home-brewing safety tips and the best home-brewing equipment to start off your brewing adventure right.

Whatever you're brewing, the underlying principle in alcoholic fermentation remains the same: you're creating a sugary liquid for yeast to eat, that, in doing so, gives off alcohol and carbon dioxide and leaves you with a pleasing final product. Now, that same sugary liquid will also look very tempting to an awful lot of microbes. Pediococcus, for example, not only produces undesirable flavours, it can also cause your brew to become 'ropey.' Nobody wants slimy strands of goo in their ginger beer, do they?

How do you sanitize your equipment?

There are two main terms in brewing to get your head around here: clean and sanitised.

Cleaning refers to soil, dirt and visible stains. This is the same level as washing crockery and cutlery. Everything you use during a brew should be spotlessly clean and free of dust or grease. Mind when cleaning plastic items that you avoid using hard scouring pads, or anything that might scratch the surface, as those little scratches are an ideal place for microbes to hide.

Sanitising is the next step up and means reducing any potential sources of microbial spoilage to irrelevant levels. That is, you're getting rid of what you can't see, to minimise the chances of anything spoiling your lovely drink. This is an integral part of brewing. This isn't very difficult at homebrew level – just clean your equipment after it has been used and you can be confident that the sanitising just before the next use will be effective.

There is a third stage, sterilising, which is the elimination of all forms of life on the object. Unless your homebrewing set-up is in a hospital clean room and you're wearing fully sealed gear, the space you brew in won't be sterile. Given that, sanitising your equipment is the best way to ensure that even at the microbial level there shouldn't be enough to cause any infection.

Keep your eye on the basic principles and the following products should see you through.

Things to remember

When using these chemicals listed below, follow any instructions on the packaging closely.
When handling anything stronger than washing-up liquid, wear rubber gloves and be mindful of splashes.
When diluting chemicals, always add the chemical to water, not the other way around.

Clean everything as soon as you are finished with it, with a cleaner/sanitiser for extra reassurance, and then sanitise your equipment right before it needs to be used. If you have a solution of no-rinse sanitiser handy to rest stirrers and the like during the brew, so much the better.

Washing-up liquid

Good for: entry-level cleaning – but not sanitising (see below for sanitisers).

When it comes to cleaning your equipment, the same detergent as you would use for washing crockery or pots and pans is fine. Some of the following cleaners are better, but if you're starting out, they aren't essential. Do be aware that any scented cleaners need to be extra-carefully rinsed off. Note that unlike most of the rest of this list, washing-up liquid won't sanitise your equipment.

Bleach

Good for: cleaning and sanitising (especially glass), but requires extra attention and care.

Don't use this neat from the bottle. Diluted suitably, this is highly effective, both as a cleaner and a sanitiser, but will react badly with some substances (it will blacken copper or brass, and cloud some plastics), so be mindful what you use it on. Even stainless steel will pit if left in too long, so don't soak anything except glass in it for more than half an hour.

There is also the fact that the flavour/aroma is detectable even in miniscule amounts, so even at safe levels of dilution, it can taint the flavour of your drink. For this reason, anything you clean with a bleach solution needs a thorough rinsing, ideally with boiled water. If you use bleach, look to get an unthickened and unscented variety. A ratio of 2ml of domestic bleach per 1 litre of water will give you a solution that will, with a few minutes soaking, take dirt off effectively when scrubbed.

Proprietary mixes

Good for: cleaning and sanitising.

There are many of these, of which VWP and PBW are the best known. They clean dirt off excellently, but also have a sanitising function, rinse off easily and leave no odour. They are reliable, manageably priced, store well, and work on a whole range of equipment.

No-rinse sanitisers

Good for: best quality sanitisation immediately before and during a brew. Do not use for cleaning.

It is best to sanitise your equipment as close to their being used as possible, and the easiest way to do this is to use a 'no-rinse' solution. Simply make up a few litres of one of these solutions and you can keep any stirrers, lengths of hose in it, ready for use. The same solution can be used to rinse your clean fermenting bucket just before use. Note that these 'no-rinse' will only sanitise, and have no cleaning power. Don't try and use them for any other purpose. Star-San and Chemsan are the two most notable brands, but there are a few out there. The dilution ratio may seem extraordinary (often all of 1.5ml per litre of water), but they work, and make life a lot simpler.

When getting bottles ready for filling day, follow exactly the same principles. If you're keeping beer bottles for reuse, a quick rinse-out of any sediment immediately after drinking makes life a lot easier when it comes to cleaning them properly. A bottle brush is very helpful for getting at anything lurking inside when cleaning them fully.
Running clean bottles through a dishwasher cycle without detergent or rinse aid will sanitise them once they're clean.

I find either submerging them in a bucket of no-rinse sanitiser, or spraying the mouth and interior with a spray bottle filled with the same, and then emptying them is effective and simple.

More information on brewing and fermenting

Home-brewing: top tips from an expert
How to make kombucha
The health benefits of fermenting
Elderflower wine recipe
Elderflower champagne recipe

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